KISSIMMEE — About 80 law enforcement officers met Thursday to learn how they can crack down on organized automobile thefts.

Sharing investigative information and techniques that they hope will help them put a dent in one of the fastest growing crimes in Florida, the officers spent a day swapping files on car thieves.

The Florida Auto Theft Intelligence Unit is made up of auto theft investigators from throughout Florida. The officers meet every three months to discuss new techniques, swap intelligence information and talk about crime patterns.

''It's a great opportunity for the officers to develop a rapport with auto- theft investigators from around the state,'' said sheriff's Lt. Larry Taggett. ''It's just a whole lot easier to deal with someone on the phone when you know who they are.''

Officers met during a barbecue at Kissimmee's Mounted Police Range on Airport Road Wednesday night; on Thursday they attended an auto-theft seminar sponsored by the Osceola County Sheriff's Department at the Hilton Gateway on West U.S. Highway 192.

Sgt. Chuck Arnold, who organized the seminar, is the auto theft investigator for the Osceola County Sheriff's Department. Arnold is assisted by Sgt. James Key.

Investigators said the need to organize is clear. In 1984, there were 46,847 cars stolen in the state, compared with 43,235 in 1983. In Osceola County there were 241 thefts, up from 190 in 1983.

The problem facing law enforcement agencies is the increasing sophistication of car thieves.

''A Porsche ordered in New York can be ripped off from someone down here, and then delivered in New York with a new paint job, plates and identification in just a few days,'' Sailor said.

These operations usually take place in chop shops, a slang term for an illegal garage where auto thieves change a car's original identification so it can be sold on the black market.

''In order for us to keep up with the the organized band of thieves, it's necessary for law enforcement officers to organize and share their techniques,'' said Sheriff Bob Fornes, whose department recovered about 75 percent of the vehicles stolen in the county last year.

Investigators said the types of vehicles likely to be taken vary from year to year. Last year, for example, thieves focused on stealing 1978 Ford vans. Later, the vehicles would be sent to South America to be used as ambulances, officers said.

Deputies said some cars are stolen by joyriders just wanting to go from one place to another.

''Most of these thefts could be prevented if people would remember to remove their keys from the car and then lock it,'' Taggett said.

However, deputies said there is very little that a person can do to stop the professional from taking your car if he wants it.

''They'll walk up to a car, insert a dummy key, then cut make a new the key and drive away within minutes,'' Sailor said.